Lattice dynamical properties of a ruthanate superconducting compound an rep
orted here by using an unscreened rigid ion model. These results show an ov
erall consistent description of the lattice vibrations in the ruthanate com
pound. Also, the phonon density of states of Sr2RuO4 show that the mixed ch
aracter of phonon modes, which is in turn responsible for the electron-phon
on interaction, is relatively very small in Sr2RuO4 in comparison to its is
ostructural cuprate superconductor La2-xSrxCuO4.